Do I Need to Replace All Tires at the Same Time When Increasing Tire Size

Question:

I am replacing at least 2 trailer tire a year. Blowouts or usually rounding no flat service on tread. I have ST235/80R16 load E towmax. I am replacing them with ST235/80R16 load F from Thurderer 501. There are still some of the Thurderers on the internet 2015 but they no longer make them. 1 Can I replace the ST235/80R16 with ST235/85R16 load G one at a time? or 2 If no to one at a time, can I replace 1 side of tires at a time. My 5th wheel has 3 axles, so can I replace 3 on one side this year with the 85 G tires and the other 3 next year with the 85 G? Thanks for the help.

asked by: John.signorelli99@gmail.com

Helpful Expert Reply:

When changing tire size it is always recommended to replace them all at once. Replacing one at a time, or even one side at a time, is likely to cause problems. If you aren't going to replace them all at once it would be better to replace them one axle at a time. This way each axle will at least have the same size tire on each side of it.

Another thing you will want to pay attention to is the amount of clearance you will lose by increasing the tire size. The tires you have now have an outer diameter of 30.9 inches. The larger tires are 31.6 inches. It is recommended that you have no less than 4-1/2 inches of clearance between the tire tread and the wheel well for bump clearance.

The frequent blowouts and rounding are common symptoms from under inflation and driving over the speed the tire is rated for. A lot of tires do not display a speed rating. However, Taskmaster # TTWPRG235R16 does rate theirs. This particular tire has speed rating M which is a max speed of 81 MPH.

expert reply by: Charles S